Acanthosis nigricans is diffuse epidermal hyperplasia (thickening of the skin). It implies increased thickness of the Malpighian layer (stratum basale and stratum spinosum).it is a skin hyperpigmentation condition which can be characterized by areas of dark, velvety discoloration in body folds.
The skin changes of acanthosis nigricans (ak-an-THOE-sis NIE-grih-kuns) typically occur in people who are obese or have diabetes. Children who develop the condition are at higher risk of developing type 2 diabetes. Rarely, acanthosis nigricans can be a warning sign of a cancerous tumor in an internal organ, such as the stomach or liver.
Disease statistics: Acanthosis nigricans prevalence rate in Spain was estimated to be present in 7.1% of the 1,412 children examined. The skin lesion was equally distributed between boys and girls and was most common among children with severe obesity. The condition was present in two of 440 white non-Hispanics, 19 of 343 Hispanics, and 80 of 601 blacks examined.